Projectile



W. H. DUNN PROJECTILE Aug. 19, 1941.

Filed July 15, 1939 Patented Aug. 19, i

UNITED STATES PATENT OFFICE 2 Claims.

The present invention relates to explosive projectiles for anti-aircraft guns and has for its primary object to provide control means for the explosives carried by the projectile and which is responsive to the air current created by the propeller of an aircraft through which the projectile is passing whereby to explode the projectile.

A further object of the invention is to provide an explosive shell of this character which includes a detonator cap and a firing pin for the cap together with a longitudinally extending air passage formed in the shell and within the rear end of which is positioned a plug which maintains the firing pin from engaging the cap and providing a shield for the front end of the air passage which normally prevents air currents from. passing therethrough during the forward movement of the shell, but which is designed to admit cross air currents, such as produced by the propeller of an aircraft, while the shell is passing therethrough, whereby to remove the plug and permit the striking of the cap by the firing pin.

A still further object is to provide a device of this character of simple and practical construction, which is efficient and reliable in performance, relatively inexpensive to manufacture and otherwise well adapted for the purposes for which the same is intended.

Further objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawing forming part hereof, wherein like numerals refer to like parts throughout and in which:

Figure 1 is a longitudinal sectional view through the shell.

Figure 2 is a transverse sectional view taken substantially on a line 2-2 of Figure 1, and

Figure 3 is a fragmentary sectional view taken substantially on a line 8-8 of Figure 1.

Referring now to the drawing in detail the numeral 5 designates the shell which is of hol low construction and of tapering form with its rear end closed by a threaded cap 6 for enclosing the explosive I within the shell.

A longitudinal air passage 8 is formed in the shell which is flared at its front end as shown at 9 and embedded in the front end of the shell are a plurality of rods l0 forming supports for a shield II which is maintained in spaced relation in advance of the front end of the air passage 8 as clearly shown in Figure 1 of the drawing.

The air passage 8 extends through the base of the shell as well as through the cap 8 and singly I! having a flange i3 formed thereon to prevent inward movement of the plug, the plug being removably secured in position by means of a paper strip or the like It cemented or otherwise secured over the outer end of the plug to prevent accidental removal thereof from the shell, during handling or loading. burned when the gun is fired.

A port I5 is formed in the shell providing communication between the explosive I and the air passage 8 and within which is fitted a detonator cap is. In the wall of the passage 8 diametrically opposite from the cap it is a firing pin ll recessed in the wall and behind which is positioned an expansible coil spring i8 to project the firing pin in a direction for striking the cap it. The pin is normally separated from engaging the cap by means of the plug l2.

In the operation of the device. when the shell is fired from the gun, the usual air resistance encountered by the shell will be prevented from entering the air passage 8 by the shield II, thus relieving the plug of such air resistance. However, upon the passage of the shell through crosscurrents, such as produced by the propeller of an aircraft, the cross-currents of air will enter the space between the shield Ii and the front end of the shell whereby to force the plug i2 from the passage, whereby the firing pin ll will be permitted to strike the detonator cap I6 and cause an explosion of the shell. The firing pin also assists in retaining the plug in the passage.

It is believed the details of construction and manner of operation of the device will be readily understood from the foregoing without further detailed explanation.

Having described the invention what I claim is:

l. A projectile comprising a hollow shell, an explosive therein, means providing an air passage longitudinally of the shell and open at its front and rear ends, a shield at the front end of the passage adapted to prevent direct entrance of air into the passage during flight of the shell under normal air conditions and adapted to admit a force of air into the passage from a direction laterally to the direction of flight of the projectile, a detonator cap and a spring-actuated firing pin therefor in the shell and a plug removably positioned in the air passage normally maintaining the pin from contacting the cap, said plug being responsive to air pressure entering the passage to release the pin.

2'. A projectile comprising a hollow shell, and explosive therein, means providing an air passage fitted in the rear end of the passage is a plug l ngi y f the shell and open at its front,

The paper retainer is and rear ends, a shield at the front end of the passage adapted to prevent direct entrance 01 air into the passage and adapted to admit a force of air into the passage from a direction laterally to the direction of flight of the projectile, a detonator cap and a spring-actuated firing pin therefor in the shell, a plug in the air passage normally maintaining the pin from contacting the cap, said plug being responsive to air pressure entering the passage to release the pin and a frangible re- 5 tainin: member for the plug.

WILLIAM H. DUNN. 

